1. Field of the Invention
The present invention relates to reflectors in satellite systems, and, more particularly, heating systems for reflectors in satellite systems.
2. Description of the Related Art
An antenna reflector, commonly called a dish, is generally a parabolic section having a round, elliptical or other configuration. A reflector functions to gather radio or microwave frequency energy transmitted from the feed horn or through the ambient environment from an external transmitter. The reflector can thus be used to receive and transmit signals to and from the satellite system. Typical applications include communicating data collected by a point of sale terminal in a store to the central data processing location. In this way, a large company can keep track of its sales and inventory requirements on an instantaneous basis. Maintaining a reliable satellite contact is absolutely essential. Reflectors are usually located outdoors, where snow and ice may collect on the receiving or concave side, degrading the performance of the reflector. If the link fails, store clerks have no way of executing any transactions with a customer. Thus, outages caused by snow and ice accumulation on the antenna reflector and feed are intolerable. In view of this, it is known to install heating apparatuses for deicing antennas in climates where snow and ice can present problems.
Keeping these earth stations operating reliably during the winter months at locations exposed to snow requires deicing the antenna reflector and feed. Small antennas almost universally employ electric heaters for this purpose. To minimize energy consumption, the heaters are automatically controlled using a snow controller. A Model LCD-3S Snow Switch, manufactured by Environmental Technologies, Inc., is an example of a typical snow controller used for this purpose.
The antenna must have an unobstructed view of the desired satellite. Thus, an antenna for the satellite terminal is often installed on the roof of the structure. It is extremely expensive to wire power line voltage to the antenna for deicing purposes. In shopping complexes, the requirement for line voltage power at the antenna site may require that a conduit be run hundreds of feet to the customer""s location. Such power line voltage must be carried in a conduit on the outside of the building, or fed through an opening in the roof, making the installation expensive. Also, such a rooftop location is not conveniently accessible.
Low voltage NEC Class 2 operation of the deicing heaters is one possible solution since no conduit is required. Unfortunately, this is not practical due to NEC power limitations. One hundred twenty-five watts is not enough power to deice other than the smallest antennas.
What is needed in the art is a heating system for a reflector which is internally powered, eliminating the need for power line voltage to be wired to the reflector.
The present invention provides a heating system for a satellite reflector including a storage capacitor which can be recharged with an electrical control system and power provided by a coaxial cable, which also carries data to the reflector.
In addition, the present invention provides remote control and monitoring of the deicing system. The point of remote control and monitoring can be either at the customer""s location for maintenance purposes or at the hub earth station. A hub earth station communicates with each of the many small earth stations in a network. The small earth stations communicate with the hub station through the satellite. Thus, the small stations cannot communicate with one another. Hub stations technician monitor the deicing system and exercise control when the need arises.
The invention comprises, in one form thereof, a heated antenna system including an antenna having a reflecting surface and a heater associated with the reflecting surface. A storage capacitor is connected with and provides power to the heater. An electronic control system is electrically connected to the storage capacitor. The electrical control system charges and monitors the storage capacitor and issues a status signal indicative of a status of the storage capacitor.
An advantage of the present invention is that line voltage does not have to be wired, with an associated additional electrical conductor, from a power outlet located inside a building to a reflector located on a rooftop.
Another advantage is that if the heater is not functioning properly, an alarm signal is transmitted to a receiver at a location of the user""s choice. Thus, the user is informed when maintenance and/or repair of the heating system is required.
Yet another advantage is that a low voltage NEC Class 2 power source can be used for deicing most small antennas.